Annual report pursuant to Section 13 and 15(d)

Accounting Policies - Additional Information (Detail)

v3.6.0.2
Accounting Policies - Additional Information (Detail)
$ in Millions
4 Months Ended 12 Months Ended 18 Months Ended
Apr. 24, 2015
USD ($)
Dec. 31, 2016
USD ($)
segment
Dec. 31, 2009
USD ($)
Jun. 30, 2016
USD ($)
Accounting Policies [Line Items]        
Maturity period of liquid investments   3 months    
Maturity period of financial instruments   Greater than three months and less than one year    
Direct and indirect development costs   $ 30.0    
Revenue recognized     $ 22.0  
Number of operating segments | segment   1    
Restricted Stock Unit Awards [Member]        
Accounting Policies [Line Items]        
Award vesting period   4 years    
Collaborative Arrangement [Member] | Teva Pharmaceutical Industries Ltd. [Member]        
Accounting Policies [Line Items]        
Proceeds from advance reimbursement research and development $ 27.0      
Hold-back amount and third-party expenses deducted from advanced reimbursement payment 3.8      
Hold-back amount deducted from advanced reimbursement payment 3.0      
Third-party expenses deducted from advanced reimbursement payment $ 0.8      
Collaboration revenue       $ 23.2